The present invention relates generally to fluid ejection devices and, more particularly, to a waste fluid collection container for collecting waste fluid ejected from such a device.
There are numerous situations where one needs to collect waste fluids. For example, if waste fluids are released inside machinery, such as a copier or printer, it can be necessary to collect these fluids so that they do not damage the surrounding machinery. Also, when changing the oil in an automobile, the oil must be collected and brought to a safe disposal location. To save the time and cost associated with emptying or changing collection containers, it is desirable to maximize the collection potential of a collection container.
Ink jet printers are a specific example of machinery that produces waste fluid, e.g., ink. In addition to ejecting ink onto paper or other substrates, ink jet printers also eject ink at other times. As part of the printhead maintenance routine, many ink jet printers eject ink periodically to keep them unclogged and working. This is referred to in the art as spitting. A printer controller will position the print cartridge at a maintenance station having a spit station or spittoon and cause the printhead to eject ink into the spittoon after a print cartridge has been away from a maintenance station for a specific length of time. The printer controller does this to prevent the ink or meniscus in the little used nozzles from drying and becoming too viscous. A receptacle is used to collect this ink in order to prevent a mess from being created and to prevent damage to other components of the printer.
Some printheads also eject ink during a priming process. For example, some priming processes involve applying a vacuum to the front face of the printhead to pull ink through the nozzles to initially prime the printhead or remove air bubbles or dried ink. A receptacle may also be used to collect ink ejected during such a priming process. When the printhead nozzle face ejects ink, ink that is removed from the nozzles (waste ink) is either ejected directly into a receptacle having a waste pad therein, or it is transported indirectly through ducts or tubing to the receptacle and waste pad via a vacuum pump and tubing.
More specifically, ink is absorbed into the pad. However, sometimes the waste pad will stop absorbing and overflow with ink. This happens because the ink does not flow through the whole pad, but flows a ways into it and stops progressing. This happens most often with inks containing carbon. The ink remains suspended some distance from the floor of the waste receptacle. The water evaporates out of the ink inside the perimeter of the hole thus impeding the ability for fresh ink to spread through the foam.
Previous receptacle designs were simply flat on the bottom. When the tar-like ink residue impedes new ink from spreading throughout the foam, the new ink fills the hole in the waste pad and rises out of the receptacle itself. This is a major concern since ink leaking out of the printer will upset the customer.
Embodiments of the present invention include a waste fluid collection container having a floor defined by a periphery. The floor has a set of raised ridges located extending outward from a central area. The container also includes a wall or walls located along said periphery and attached to and surrounding the floor. The container further includes a fluid absorbing member that sits inside the collection container.
Other embodiments of the invention include a waste fluid collection container having a floor having a plurality of cylindrical studs thereon. The container also includes a wall located along said periphery and attached to and surrounding the floor. The container further includes a fluid absorbing member that sits inside the collection container.